Electrically conductive pastes containing metal nanoparticles have been used in forming a circuit pattern on a circuit board or a conductive layer of an electrode. In this case, the circuit pattern or conductive layer has been formed by applying the conductive paste onto a substrate by, for example, screen printing. Japanese Laid-Open Patent Publication No. 2013-140991 discloses a composition that contains metal nanoparticles, an organic polymer and a dispersion medium. The composition is used for producing an electrode of a solar cell by being applied onto a substrate, and then baked.
Also disclosed is a method for forming a circuit pattern using an ink containing metal nanoparticles. Japanese Laid-Open Patent Publication No. 2010-80095 and Japanese Laid-Open Patent Publication No. 2013-112807 disclose an electrically conductive ink that contains at least a polymer compound and metal nanoparticles. The latter publication evaluates a volume resistivity using a baked product of an applied film of the ink.